DE2401440C3 - Process for the production of a glue-on coating film - Google Patents

Description

The invention relates to a method of manufacture a removable coating film for the surface coating of wood-based panels by impregnating a carrier sheet with the solution of a Aminoplast resin drying the impregnated web with simultaneous precondensation of the introduced Synthetic resin and embossing a surface structure by means of a device suitable for this purpose.

For tempering the surfaces of wood-based panels With backing sheets soaked with curable resins, one can basically get two use different procedures. One can soaked and coated with curable resins on one Films that have been dried to a certain Darrwert, but still permeable;. on wood-based material surfaces below Press on curing conditions, at the same time the bond between the film and the surface tier Wood-based panel and a surface of the film corresponding to the surface of the press plate is formed under curing conditions. It is possible to use a press plate which a structured surface, which is then communicated to the hardening synthetic resin surface.

However, it is also possible to impregnate the carrier web with smaller amounts of aminoplast resin and to precondense it during drying to such an extent that the resin no longer flows or flows only slightly during the prepressing. The impregnated and condensed carrier web is glued to the surface of a wood-based panel by means of a conventional gluing technique. This method is of particular interest when the processor, e.g. B. the furniture manufacturer, only has Verleimimgspressen available with which a relatively low pressure, t. B. one of 5 kp cnr '. can be exercised. The invention relates to this latter mode of operation.

It is known that supporting webs / .. for example, those containing Aniinoplastharz may be provided by calendering with a surface structure. According to the prior art, the carrier web containing the amine plastic precondensate is dried to a final dryness value of <V '< and only then structured by calendering. The Darrwert corresponds to the weight loss after heating for 5 minutes at 160 ° C in a drying cabinet. However, this method has a number of disadvantages. A disadvantage is that the carrier web, which has been dried to such a low kiln value and contains condensed synthetic resin, is relatively brittle and therefore tears, breaks and similar processing difficulties during structuring. In addition, the pressure to produce the structures must be relatively high, since the resin-impregnated.

ίο condensed carrier web only a little '. ¹ shows plastic deformation. With a line pressure of H to 10 t / cm during calendering, only pores or surface structures of relatively small depth are obtained. This cannot be improved even if the structuring is carried out at an elevated temperature. In the case of carrier webs weighing less than 100 g / m ^2, even flat embossings will pierce the resinous paper web.
The object of the present invention is to eliminate these disadvantages.

This object according to the invention is achieved in that the resin-coated carrier web is first dried to a kiln value> 4 to H ^r / i , then structured in the usual way and only then dried and condensed to a kiln value of <4%. The essence of the invention is that the structural calendering process is carried out at a higher kiln value and the structured process product is then condensed further to the kiln value required for the application.

The advantage of the method according to the invention can be seen from the following comparison. There are two coating films. The coating film A corresponds to the state of the art and has a kiln size of <40i, while the layering film H has a kiln size of 4 to ti'r . Both foils are now embossed with the same calender to create a surface structure. In order to obtain the same pore depth in the two foils, it is necessary to apply a higher pressure to foil A. After structuring, film Ii is now brought to the same kiln value as film A. Externally, both foils are identical. They have the same structure and the same pore depth. But if you glue these coating foils z. . As in IW C "M) seconds and a pressure of 5 kgf / cnr to llolzoberllächen on, there is a clear difference: When Aufleimung the surface structure of the film A is partially equalized, while the surface structure of the film Ii retain such. The effect of the different stability of the structure is surprising and was not foreseeable.

With the method according to the invention it is thus possible to achieve the line pressure required for structuring during calendering to about the envelope of the usual pressures. Another advantage The method according to the invention consists in that a deeper deformation is possible and later Gluing and pressing the condensed, structured carrier web the surface structure on the entire surface is well preserved and not, as in the case of products of the prior art, partly pushed away will.

Another advantage of the general procedure consists in that one. due to the lower pressure when structuring the surface and the better deformability of the resin included-

3 4

the carrier web, papers with a lower paper weight. Precondensates of the synthetic resin to a Darrwert

weight can use. This leads to a loss of 2.5 %. Afterward

Β delivery of the procedure. the dried, resinated paper web was also

I The method according to the invention is to be carried out on the basis of an embossing calender with a line

H the following examples are explained in more detail. 5 pressure vrni s tem.

1 . . . . The X'erfahreiisprodukt was under the same example conditions using a urea resin on a f | KOg / m 'heavy, with a decor printed Pa chipboard glued on.

'pier was soaked in a solution of urine stole. The pore depth of the obtained which contained 50 parts by weight of solids was then determined. The i ₀ surface with a measuring device to determine the

, ·; Soaked shark was determined by heating at a temperature roughness depth. The measurement diagram showed none

: | Doors from 140 to! 6 (I "C dried. A striking pore pattern appeared. The maximum pore depth was

I precondensates of the synthetic resin on a Darrweri 30 _{J (} .
U from T'i Kotfeuchtc a. With this residual moisture

The pore structure was embossed using an embossing calender. The line pressure was S t cm. So g / m-heavy pail printed with a decor. The hardened and structured pier was then impregnated with a urea resin solution. [J the web on a kiln of 2.5 " residual moisture which contained 50 percent by weight solids. The dryness. The Ilar / content was 40 gnv. The soaked web was heated at temperature of 14 ( dried at 160 "C. In the process, urine resin glue was glued onto a chipboard. The precondensation of the synthetic resin to a kiln value takes place in a press at LUl" C. with residual moisture from Ti . With this residual moisture content .U) Seconds a pressure of-ikp. Cm "was maintained by means of an embossing calender. embossed structure. The line pressure was 4 t / cm. : When measuring the pore size with a rough surface, the resin-coated and structured;.; Fen-Vleßgeriit resulted in a distinctive pore pattern. The web to a Darrwert of 2.5% residual ^moisture: maximum Porenticfc was KK) //. dries. The Ilar / content was 40 g / m '.

If, on the other hand, comparison is made according to the The process product obtained was as in

: State of the art an identical paper with the same previous examples on a chipboard

· ■■ Urinary solution in turn soaked that the ₃ :, glued.

'■■': Process product 40 g, m 'I lar / contains, but the When measuring the pore depth with a roughness

ϊ soaked web under heating at temperatures of fen measuring devices resulted in a distinctive pore pattern. the

'. 140 to IhO "(" dried until a pre-condensate maximum pore depth was 60/1.

i .. of synthetic resin on a Darrwer! from 2.5 ^{r /} i residual / um comparison, the same paper was again

• light has entered and then the gctrock- _{35 m} jt soaked the urea resin solution that the

ί netc.hehar / te paper web through an embossing calender contains 40 g / m ^{2 of} resin. The soaked

\ at a line pressure of K tem, so shows web was then but heated at tempera-

■ the measuring diagram of the with a depth of measurement door of 140 to 160 "(" dried to a pre-con

f advises certain pore depth of the surface of the under densation of the synthetic resin to a Darrwert of

'■' the same conditions as above on a chipboard ₄ "2,>'r residual light had occurred. Afterward

, ■ glued-on procedural proiliiktes no distinctive, the dried, hard / te paper web through egg

Pore pattern. The maximum pore flow beting M) 11 .

'' pressure of 15 t / cm.

Example 2 D _{; ls} \ _cr | _: Was dirensprodukt under the same 105 g / nr heavy, with a decoration printed 45 conditions as in ilen preceding Br'spielen paper was impregnated with a urea resin solution having an I lai iistolfhar / Leini on a particle board aufweiche 50 weight percent solids contained. The glued.

The impregnated web was heated at temperature. The resinous paper web was dried by the test at 140 to 160 ° C. In the process, a process occurred partially pierced. Precondensation of the synthetic resin on a Darrweri 50 glue occurred through the pores, resulting in a perfect coating of the 7% residual moisture. With this residual moisture >> chehtened chipboard is no longer possible. The pore depth was then embossed into the structure obtained using an embossing calender. The line pressure was 8 t / cm. The surface with a roughness depth measuring device was then resinated and structured. The measurement diagram did not show a distinctive bottom line on a drying value of 2.5% residual moisture. The maximum pore depth was .Ul μ. dries. The Ilar / content was 50 g / cm '. Comparing the results according to the invention, the product obtained was glued onto a chipboard as indicated in the method with a line pressure of 4 t / cm. Example I. When the pore depth was measured with a prior art roughening device in accordance with the Verfen measuring device, a distinctive pore pattern resulted. The same 60 in example I shows that the maximum pore depth was 100 //. According to the method according to the invention with a line pressure / um comparison, the same paper was again of 4 t / cm a pore depth of 60 μ, soaked in the process with the same urea resin / solution that that of the prior art in the double line process product contains 50 g of resin. The pressure, namely a line pressure of H t cm. only the troughed path then became half the pore depth when heated at 65, namely one of .U) //. Temperatures of 140 to 160 "C dried until one could be erli,! En.

Claims (1)

24 Ol 440 Claim: Process for the production of a glue-on coating film for surface coating of wooden boards by impregnating a carrier sheet with a solution of an aminoplast resin. Drying of the impregnated web with simultaneous precondensation of the introduced Synthetic resin and embossing a surface structure using a suitable device, characterized in that the resin-coated carrier tap is initially set to a Darrwert > 4 to S'-i dries, then in the usual way structured and only then dries and condenses to a Darrwert <4Ci.